1. Field of the Invention
The present invention relates generally to marine exhaust systems for use with internal combustion marine engines, and more particularly to an improved marine muffler having an inclined baffle assembly and tunable pulse attenuation exhaust conduits that provide improved exhaust noise silencing.
2. Description of Related Art
Marine vessels are typically configured with a propulsion system powered by an internal combustion engine mounted within the vessel hull. Exhaust generated by the engine is commonly combined with cooling water and routed through exhaust conduit to the stern of the vessel via one or more exhaust ducts where the exhaust is discharged through one or more exhaust ports formed in the transom. One or more mufflers are installed within the exhaust duct(s) to silence noise associated with the engine and exhaust gases.
A variety of structures are known in the background art for use in silencing marine exhaust noise. The present inventor has invented a number of novel marine exhaust components that have greatly improved the silencing and efficiency of marine exhaust systems. Among those inventions developed by a named inventor for the present invention are the following:
U.S. Pat. No.Entitled4,918,917Liquid Cooled Exhaust Flange5,196,655Muffler for Marine Engines5,228,876Marine Exhaust System Component Comprising a HeatResistant Conduit5,262,600In-line Insertion Muffler for Marine Engines5,444,196In-line Insertion Muffler for Marine Engines5,504,280Muffler for Marine Engines5,616,893Reverse Entry Muffler With Surge Suppression Feature5,625,173Single Baffle Linear Muffler for Marine Engines5,718,462Muffler Tube Coupling With Reinforcing Inserts5,740,670Water Jacketed Exhaust Pipe for Marine Exhaust Systems.6,564,901Muffler for Marine Engine7,581,620Marine Muffler with Angularly Disposed Internal Baffle7,905,322Marine Muffler with Angularly Disposed Internal Baffle7,942,238Marine Muffler with Angularly Disposed Internal Baffle8,246,403Marine Water Drop Muffler8,651,907Water Jacketed Marine Exhaust Components HavingMultiple Stream Spray Ring Configurations
In U.S. Pat. No. 5,262,600, the first named inventor herein disclosed an in-line insertion muffler for marine engines employing a first housing encompassing a second housing which is partitioned by an angularly disposed inner planar baffle that has proven extremely effective in reducing engine noise. In U.S. Pat. No. 5,444,196, the first named inventor herein disclosed an improved version of the in-line muffler having a corrugated sleeve disposed between in the first and second housings. In U.S. Pat. No. 5,625,173, the first named inventor herein disclosed a single baffle linear muffler with an angularly disposed baffle that may be planer, convex, or concave. In U.S. Pat. No. 7,581,620, the first named inventor herein disclosed a marine muffler comprising an elongate cylindrical housing having an inlet and an outlet, and an internal volume partitioned by an angularly disposed internal baffle into a lower chamber in communication with the inlet and an upper chamber in communication with the outlet. A centrally disposed duct passes through the baffle to allow exhaust gas and exhaust cooling water to flow from the lower inlet chamber to upper outlet chamber.
The various linear mufflers made in accordance with the above-referenced patents have achieved tremendous success and widespread acceptance within the marine industry. Such muffler systems have been successfully installed on a wide variety of marine vessels having engines in excess of 1,000 horsepower. Due to the myriad engine packages and exhaust configurations, there exists a need for advancements in marine mufflers that allow for structural adjustments to the muffler to optimize sound suppression and minimize backpressure for specific engine makes and models.